With the development of communication technology, Machine-to-Machine Communication (M2M) is widely applied. The M2M communication is a network-based application and service centering on intelligent machine interaction. By embedding a wireless or wired communication module and application logic module, the M2M communication implements data communication without manual intervention, so as to meet informatization requirements of users for monitoring, scheduling, data collection, measurement, and so on.
FIG. 1 shows a typical M2M system architecture. The system architecture includes M2M terminals, an M2M gateway, an M2M service platform, and an M2M application.
An M2M terminal, such as a sensor and a microcontroller, is configured to receive a service instruction sent by the M2M application, and perform a service operation according to the received service instruction; the M2M gateway, as a proxy server between the M2M terminal and a transport network, is configured to provide a proxy service for an M2M terminal connected to the gateway; the M2M service platform is configured to provide a shared M2M function for the M2M application; the M2M application, such as power meter reading or intelligent transportation, is configured to use a service capability, provided by the M2M service platform, to acquire data collected by the M2M terminal or perform remote control and management on the M2M terminal.
In the M2M system, an M2M terminal accesses the M2M service platform directly, or remotely through the M2M gateway. By using the service capability provided by the M2M service platform, various M2M applications acquire data collected by the M2M terminal or perform remote control and management on the M2M terminal.
In the M2M system, a group communication capability is particularly important. Currently, the M2M technical specification (TS) 102 690 and TS 102 921 formulated by the European Telecommunications Standards Institute (ETSI) describe a resource-oriented group communication method. In this method, resources such as an M2M application, an M2M service platform, an M2M terminal, and an M2M gateway, including all local applications and data objects running on the M2M terminal and M2M gateway, are all considered as a kind of Representational State Transfer (RESTful) group resource. The RESTful group resource is uniquely identified by a Universal Resource Identifier (URI). A group-based operation can be performed on multiple resources by including the preceding resources as a member of the group resource. That is, the M2M application can operate the group resource at a time through a subscription device, to obtain information of group member resources on all group member devices, thereby reducing the communication payload.
However, the preceding method is only suitable for a subscription device to send an operation request to group member devices. When the group member devices send notification messages to the subscription device, too many messages are exchanged between the group member device and the subscription devices, which results in heavy communication traffic.